According to a report from Giant Freakin Robot, Secret Wars will “at least” involve Ian McKellen if it thoroughly follows the Johnathan Hickman-written Secret Wars from 2015 as the source material. The report says:
To be fair, the Multiverse plot of Phases 5 and 6 opens endless possibilities for beloved former actors to reprise their iconic roles. Phase 4 films like Spider-Man: No Way Home and Doctor Strange in the Multiverse of Madness have already offered fans how the Multiverse and variants work, which is a subtle implication that Secret Wars may be the MCU’s biggest crossover film of all time. Considering how massive Avengers: Endgame was, Marvel Studios certainly have to beat their own feat. The decision is entirely up to Marvel Studios President Kevin Feige on how he plans to develop Avengers: Secret Wars into live-action. But if we’re going to analyze the current MCU roadmap, after the studio triumphantly brought back two former Spider-Man actors Tobey Maguire and Andrew Garfield, it’s a no-brainer that they could do the same for Magneto. Stay Tuned for more updates about the X-Men!
Also read: Nicolas Cage Reportedly Returning as Ghost Rider in Marvel Secret Wars